The invention relates to devices for opening, filling, and sealing plastic bags and other packaging. More particularly, the invention relates to automated devices that can produce an air-tight seal when packaging bulky products.
Bag opening and filling devices have been developed for a wide variety of applications. Typically, these devices include one or more mechanisms for selecting a single bag from a stack of flattened, usually folded bags, and holding the selected bag open for filling. Prior-art devices commonly include a wicket that holds a stack of bags to be filled. Bags are torn from the wicket and opened prior to filling. Once the bag is opened, a pusher mechanism loads the product into the bag and a sealing mechanism seals the bag after the product has been loaded.
In modem packaging applications many different types of products are loaded into bags. It is difficult to obtain an air-tight or hermetic seal using available automated sealing equipment when packaging bulky products, such as diapers, sanitary napkins, paper napkins, and similar products. Fortunately, it is unnecessary to package these types of products in air-tight bags. However, there are applications that require hermetic sealing of the bag.
Packaging medical supplies is one such application. Hermetic sealing is required to ensure that the medical supplies are not contaminated after they are packaged and sealed in the bags. Attempts to automate the packaging and sealing of bulky medical supplies have been unsuccessful due to the problems associated with placing a bulky object in a flat bag and then attempting to bring the open edges of the bag together for sealing. The open edges wrinkle, which prevents the formation of a proper seal along the entire length of the bag opening. Consequently, bulky medical supplies are packaged and sealed by hand to ensure that a hermetic seal is produced. Manual packaging and sealing has several deficiencies. It is cumbersome, time-consuming, and vulnerable to human error.
Thus, there is a need for an automated packaging device that can be used to package medical supplies and other products in bags and to hermetically seal the bags. In addition, it would be beneficial if such a machine could monitor the quality of the seal. Further still, there is a need for a device where a relatively large number of bags can be loaded or otherwise provided to the packaging device so that product can be packaged at a relatively high rate without the need for replenishing the supply of bags at a similarly high rate.
In one embodiment, the invention provides an automated bag filling station or packaging device capable of rapidly packaging medical supplies and other bulky products in bags and sealing the bags in an air-tight manner. The packaging device includes a bag manipulating assembly for a bag filling device. The bag manipulating assembly includes a pair of bag grippers that receive and grip opposing side edges of a bag positioned in a loading station. The bag grippers are movable in a plane substantially normal to a longitudinal axis of the loading station. The bag manipulating assembly also includes upper and lower bag spreader assemblies, each having a suction cup to apply suction to the bag and a spreader plate that is insertable into the bag and movable to spread apart the bag.
In one aspect of the invention, the bag grippers move toward each other in a plane substantially normal to the longitudinal axis while the bag is being spread apart to facilitate opening the bag. To facilitate closing and sealing the bag, the bag grippers move away from each other in a plane substantially normal to the longitudinal axis after the bag has been filled.
In another embodiment, the invention provides a method of packaging an item in a bag using an automated packaging device. The method includes loading an open end of a bag into a loading station, gripping opposing sides of the bag with respective bag grippers as the bag is loaded into the loading station, opening the open end of the bag with a bag spreader assembly, loading the item into the bag with a package loading assembly, and sealing the open end of the bag with a welding assembly after the item has been loaded into the bag. Each of the bag grippers maintains the grip on the bag while the bag is opened, the item is loaded, and the open end is sealed so that control of the bag is maintained throughout the packaging process.
In one aspect of the invention, the bag grippers are moved toward one another, preferably via cam action or linear actuators, while the bag is being opened to facilitate opening the bag. To facilitate closing and sealing the bag, the bag grippers are moved away from one another after loading the item into the bag and before sealing the open end of the bag. This movement also preferably occurs via cam action or linear actuators.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.